| 摘要: |
| 为了分析制冷剂相态变化对动力电池直冷系统温控性能的影响，提出一种基于电池等效电路模型和热阻网络模型的电热耦合分析方法并建立典型电池直冷系统的离散化模型，运用AMESim对直冷系统的温度响应进行数值研究。利用实验数据进行对比验证，通过参数化研究分析动力电池的局部温控性能，获得2C高倍率充电和循环充放电工况下直冷系统的温控性能。结果表明，直冷板内制冷剂气液两相区和过热单相区的变化对系统性能存在显著影响，相比于传统的液冷系统，两相区能使电池最高温度降低28.3%，但过热区存在严重的传热恶化，造成电池最高温度显著升高和最大温差急剧增加，对于2C工况，当制冷剂从两相换热变为单相换热时，换热系数降低约73.6%，使得对应电池单元温度升高约12~14 °C；制冷剂温度过低会造成电池垂直方向温差过大，制约直冷系统在实际中的应用；提高制冷剂蒸发压力和两侧布置直冷板能够有效减小电池垂直方向的温差，但难以消除过热现象对系统性能的影响。 |
| 关键词: 电池热管理 直冷系统 电热耦合模型 相态变化 过热 |
| DOI： |
| 投稿时间：2022-07-05 修订日期：2022-09-05
录用日期：2022-10-26 |
| 基金项目:浙江省自然科学基金 |
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| Influence of Refrigerant Phase Change on Temperature Control Performance of Direct Cooling System for Power Battery |
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| Abstract: |
| In order to reveal the influence of refrigerant phase change on temperature control performance of the power battery cooling system, an electric-thermal coupling analysis method was proposed by combining battery equivalent circuit model and thermal resistance network model. Subsequently, a discrete system model was built based on AMESim. Numerical research on the temperature performance of power battery was conducted, which were verified with experimental data. Afterwards, parametric research was conducted to obtain temperature control performance of power battery cooling system, including temperature control performance under 2C high-rate charging and cyclic charge-discharge conditions. The results show that liquid-vapor heat transfer region and overheated heat transfer region of refrigerant in cooling plate have a significant impact on temperature performance. Compared with the traditional liquid cooling system, the liquid-vapor region of the direct cooling system can reduce the maximum temperature of the battery by 28.3%, while overheated region leads to significant heat transfer deterioration and increases the maximum temperature and temperature difference. When refrigerant changes from liquid-vapor heat transfer to overheated vapor heat transfer under 2C condion, heat trasnfer coefficient is reduced by 73.6% which raises the temperature of battery units by 12~14 °C. Besides, too lower temperature of refrigerant will increase the maximum temperature difference which restricts the practical application of direct cooling system. Increasing evaporating pressure and configuring plates two sides can decrease temperature difference along vertical direction. However, these two methonds cannot eliminate the influence of overheating on the performance and it is necessary to design new system to solve the problem of heat deterioration from refrigerant overheat. |
| Key words: Battery thermal management direct cooling system electrothermal coupling analysis phase change overheating |
